Monday, August 24, 2009

Large quantities of often toxic underground water, hitherto a serious barrier to coal seam gas extraction, could become valuable in its own right with careful planning, according to water purification engineers.

Names such as Origin Energy and ConocoPhillips, Santos and Petronas, the UK's BG Group and China National Offshore Oil Corp, Arrow Energy, Shell and others are in a scramble to invest billions of dollars to extract underground methane gas from coal areas such as the Surat and Bowen Basins in Queensland or the Gunnedah Basin in NSW.

But to do this they have to extract and dispose of large amounts of often saline, sometimes quite toxic underground water.

On October 30 last year, the Queensland government barred the previous practice of simply dumping the water in large evaporation ponds, which could be the size of several football fields, It ordered coal seam gas producers to find less environmentally damaging disposal methods for the water, not to mention cleaning up the existing evaporation ponds within three years.

What is a nuisance now as toxic waste water could be converted into useable water for stock watering, irrigation, watering of forestry plantations or even town water augmentation, say water processing specialists.

The best solution would be to pipe the water to a small number of centrally located purification plants, according to water engineer Vaughan Pearce of the water planning and design division of engineers MWH. This would aggregate a steady flow of water from several individual bores over 20 to 30 years, for optimum processing of different grades of water over an economic amortisation period.

Uses could include agriculture and horticulture immediately around the processing plants, extending even to glasshouse crops.

"The blueprint should be set in the Surat Basin," Mr Pearce said. "We would have an emerging industry, be able to set the economies and refine the management."

"It would give greater certainty with environmental issues, you'd be more certain of supply and quality. The industry is on the verge of massive expansion."

On cue, Australian desalination plant proponent EES Tech has agreed to provide its thermal desalination technology to water purification group Impulse Hydro for application to coal seam gas projects, with one contract already signed. The contract provides that this plant will be available for inspection as a test site for other potential customers.

EES Tech chief executive Murray Railey said the company's JetWater thermal desalination would be added to reverse osmosis water purification systems to take the percentage of useable output water from less than 75%, from osmosis alone, up to 97 per cent from the combined application.

"This has widespread immediate application to the growing coal seam gas industry in Australia, as well as in other mines which will be required to clean their waste water before it can be discharged," he said.

EES Tech holds the rights to three environmentally sustainable technologies which could be applied in coal mining.

Impulse Hydro chief Earle Roberts said: "Because of the efficiency of the combined systems the eventual market for the units in the coal seam gas industry could exceed $50 million over the next three years."

From any individual bore, the flow of water is strongest over the first three years. Government co-ordination of individual industry projects, with waste water piped up to 50 kilometres or more to central plants, would allow varying flows from different sites to be averaged out, and lightly contaminated water segregated from toxic flows requiring more intensive processing.

One expedient to be treated with caution is simply reinjecting the water into the ground after extraction of the methane coal seam gas. In the United States, after some years of this practice, local communities are finding previously pure aquifers becoming contaminated with saline water and toxic waste products.

One possibility for the Queensland government might be to establish a centre of excellence for saline water management, MHW's Mr Pearce said.

4 Comments:

- The Queensland Government has committed to tightening current legislative requirements for the disposal and beneficial reuse of coal seam gas (CSG) water.

- CSG producers with existing evaporation ponds are required to remediate those ponds within three years – although the Discussion Paper provides no detail as to how this is to be enforced.

- All existing and intending CSG producers must allow for the cost of treating CSG water and the cost of disposal of the saline effluent from that treatment.

- CSG producers will need to adopt a much broader perspective on CSG water disposal and should expect government 'encouragement' (at the least) to contribute to the development of a system to transport all treated CSG water to locations with greater potential uses.

- CSG producers – in particular, producers with existing evaporation ponds or proposed CSG operations – should make submissions to the Queensland Government by 1 June 2009 on preferred methods of evaporation pond remediation and saline effluent disposal.

I understand that Sunwater in Brisbane is proposing to construct a water grid in the Surat that will collect and distribute treated CSG Water backed up by supply from the Dawson River and deliver it to offtake customers such as coal mines. Also thay are planning to give a presentation at the conference to be held this week in Toowoomba so look out for that!

Sunwater is promoting a water grid for the receival and transport of treated CSG Water and water from the Dawson River as security of supply for when the CSG water begins to deplete.

My understanding is that there has been great interest from coal mines and other industries that need water to get operational and support the Surat Rail line to the coast.Should this Grid get up and be promoted by Government as the way to go, the Surat down to Toowoomba could become a very rich industrial area not to mention a food bowl for Australia employing many instead of just a few in the CSG fields. Apparently the CSG producers are not having a bar of it as they all have there own solution and collectively want to do as little as possible as water will only give them a minimal return (it is classed as a waste product apparently).

The salt in the water is a bigger problem and an industry could be built up around this to process a waste product into viable commodities for glass production etcGet behind this grid and support it, it means jobs jobs jobs and sustainable industrial growth for the future of Toowoomba and the Surat!

About Me

For over 6 years, the 4350water blog has informed readers of plans by the Toowoomba City Council (now Toowoomba Regional Council) and the Qld government to introduce recycled water for drinking in Toowoomba.
It has also looked at the issue from a State and Federal perspective and dealt with related State and Federal political issues.
There continues to be a need for the Toowoomba Regional Council to be completely transparent in its dealings with the ratepayers and residents of Toowoomba.
There also continues to be a need for open debate on the benefits and risks of potable reuse and long-term studies on the effects on humans of drinking recycled water.
Coal seam gas water is emerging as a possible alternate water source for some uses for the region.
The 4350water blog is a collective effort and thanks go to its many contributors.